A jointed body of a metal and a resin is used in various fields, and adhesiveness between the resin and the metal member is important for improving reliability. For example, a 42 alloy and the like have been used as a material for a lead frame in the semiconductor field. However, use of copper is the mainstream these days in order to correspond to high performance semiconductors such as high speed semiconductors. One of the methods for packaging semiconductor is a method for using a resin.
A method for sealing with a resin is widely used because of a low price and excellent workability. However, there has been a problem in which deference of coefficients of thermal expansion between the resin and a lead frame material generates a gap between a lead frame and a resin package, and thereby, a semiconductor element deteriorates caused by inflow of water. Particularly, when copper is used for the lead frame, an oxide film is generated on the surface. This causes deterioration in adhesiveness between the lead frame and the resin. In order to solve the problem described above, the following four methods are mainly used.
(1) Method for Plating on Lead Frame
For example, a method for improving connection durability by plating Ni—Sn on the lead frame is described in Japanese Unexamined Patent Application Publication No. Sho 56 (1981)-17048 is exemplified.
(2) Method for Applying Silane Coupling Treatment on Lead Frame
For example, a method for manufacturing a lead frame including a process of primer treatment with a silane coupling agent in a region corresponding to a package area of the lead frame is described in Japanese Examined Patent Application Publication No. Hei 8 (1996)-34276.
(3) Method for Modifying Resin
A method for introducing a silane coupling agent into a resin is proposed. For example, a method in which a resin including an epoxy resin, a phenolic resin curing agent, a metal salt compound represented by a general formula Mx(HyPO4)z.mE2O, an aminosilane coupling agent, a mercaptosilane compound, and an inorganic filler is used in order to provide a semiconductor sealing material having excellent adhesion to nickel plating and excellent moisture resistance and moldability as a sealing material for a power transistor is described in Japanese Unexamined Patent Application Publication No. 2003-342451 is included.
(4) Other Surface Treatment
For example, a method for forming a polydopamine film by contacting a dopamine solution onto a substrate surface to improve adhesiveness to an adhesive is described in Japanese Unexamined Patent Application Publication No. 2010-144148.